使用TabLayout+ViewPager实现顶部导航栏

添加依赖

compile 'com.android.support:support-v4:23.4.0'
compile 'com.android.support:design:23.4.0'

创建Fragment

fragment1.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:orientation="vertical">

    <TextView
        android:id="@+id/textView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        android:text="Page1"
        android:textSize="30sp"/>
</LinearLayout>

Fragment1.java

public class Fragment1 extends Fragment {
    
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater,
                             @Nullable ViewGroup container,
                             @Nullable Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment1, container, false);
    }
    
}

这里只展示Fragment1，其它类似。

自定义Adapter

MyFragmentPagerAdapter.java

public class MyFragmentPagerAdapter extends FragmentPagerAdapter {

    private String[] mTitles = new String[]{"购物", "发现", "主页","热点"};

    public MyFragmentPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        if (position == 1) {
            return new Fragment2();
        } else if (position == 2) {
            return new Fragment3();
        }else if (position==3){
            return new Fragment4();
        }
        return new Fragment1();
    }

    @Override
    public int getCount() {
        return mTitles.length;
    }

    //ViewPager与TabLayout绑定后，这里获取到PageTitle就是Tab的Text
    @Override
    public CharSequence getPageTitle(int position) {
        return mTitles[position];
    }
}

这里的适配的作用是将Fragment与ViewPager进行适配

使用背景选择器

tab1_selector.xml

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_selected="true" android:drawable="@mipmap/icon_cartfill_press"/>
    <item android:drawable="@mipmap/icon_cart"/>
</selector>

这里只展示tab1_selector，其它类似。

编写Activity

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              xmlns:tools="http://schemas.android.com/tools"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:orientation="vertical"
              tools:context=".MainActivity">

    <android.support.design.widget.TabLayout
        android:id="@+id/tabLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

    <android.support.v4.view.ViewPager
        android:id="@+id/viewPager"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"/>
</LinearLayout>

MainActivity.java

public class MainActivity extends AppCompatActivity {

    private TabLayout mTabLayout;
    private ViewPager mViewPager;

    private MyFragmentPagerAdapter myFragmentPagerAdapter;

    private TabLayout.Tab one;
    private TabLayout.Tab two;
    private TabLayout.Tab three;
    private TabLayout.Tab four;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //初始化视图
        initViews();
    }

    private void initViews() {

        //使用适配器将ViewPager与Fragment绑定在一起
        mViewPager= (ViewPager) findViewById(R.id.viewPager);
        myFragmentPagerAdapter = new MyFragmentPagerAdapter(getSupportFragmentManager());
        mViewPager.setAdapter(myFragmentPagerAdapter);

        //将TabLayout与ViewPager绑定在一起
        mTabLayout = (TabLayout) findViewById(R.id.tabLayout);
        mTabLayout.setupWithViewPager(mViewPager);

        //指定Tab的位置
        one = mTabLayout.getTabAt(0);
        two = mTabLayout.getTabAt(1);
        three = mTabLayout.getTabAt(2);
        four = mTabLayout.getTabAt(3);

        //设置Tab的图标，使用背景选择器
        one.setIcon(R.drawable.tab1_selector);
        two.setIcon(R.drawable.tab2_selector);
        three.setIcon(R.drawable.tab3_selector);
        four.setIcon(R.drawable.tab4_selector);

    }
}

效果如下